Manager Steve Bruce said: "O'Shea's wealth of experience and versatility will be great attributes for us."

The Black Cats had a joint bid for O'Shea, Brown and midfielder Darron Gibson accepted last month, but the move for the third of the trio seems to have slowed.

Brown, 31, and O'Shea will add experience to a Sunderland defence that was badly affected by injuries last season.

I'm delighted with the players we've been able to secure ahead of the new season

Steve BruceSunderland manager

Bruce added: "John has been a solid, consistent part of Manchester United's squad for well over a decade which goes to show the fantastic pedigree of player we have signed.

"He is a wonderful professional both on and off the field.

"I'm delighted with the players we've been able to secure ahead of the new season."

O'Shea, who has only ever played for United in his career, added: "Once I'd heard reports about the club and the people here, the ambitions and what the manager was all about, this was the only place I was going to come to."

As well as the United duo, Bruce has already completed a double raid on Birmingham by signing midfielders Craig Gardner and Sebastian Larsson, and brought in Ipswich striker Connor Wickham for an initial fee of £8.1m.

South Korea striker Ji Dong-Won and Coventry goalkeeper Kieren Westwood have also arrived, while the club have completed a permanent move for Egypt winger Ahmed Elmohamady after his loan spell last season.